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  2. Oxygen reduction reaction - Wikipedia

    en.wikipedia.org/wiki/Oxygen_reduction_reaction

    Rather than combustion, organisms rely on elaborate sequences of electron-transfer reactions, often coupled to proton transfer. The direct reaction of O 2 with fuel is precluded by the oxygen reduction reaction, which produces water and adenosine triphosphate. Cytochrome c oxidase affects the oxygen reduction reaction by binding O 2 in a heme ...

  3. Sabatier reaction - Wikipedia

    en.wikipedia.org/wiki/Sabatier_reaction

    In an automated system, the carbon deposit may be removed by blasting with hot Martian CO 2, oxidizing the carbon into carbon monoxide (via the Boudouard reaction), which is vented. [ 25 ] A fourth solution to the stoichiometry problem would be to combine the Sabatier reaction with the reverse water-gas shift (RWGS) reaction in a single reactor ...

  4. Heterogeneous water oxidation - Wikipedia

    en.wikipedia.org/wiki/Heterogeneous_Water_Oxidation

    Under acidic conditions water binds to the surface with the irreversible removal of one electron and one proton to form a platinum hydroxide. [4] In an alkaline solution a reversible binding of hydroxide ion coupled to a one electron oxidation is thought to precede a turnover-limiting electrochemical step involving the removal of one proton and ...

  5. Standard enthalpy of formation - Wikipedia

    en.wikipedia.org/wiki/Standard_enthalpy_of_formation

    For many substances, the formation reaction may be considered as the sum of a number of simpler reactions, either real or fictitious. The enthalpy of reaction can then be analyzed by applying Hess' law, which states that the sum of the enthalpy changes for a number of individual reaction steps equals the enthalpy change of the overall reaction.

  6. Thermochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Thermochemical_cycle

    In chemistry, thermochemical cycles combine solely heat sources (thermo) with chemical reactions to split water into its hydrogen and oxygen components. [1] The term cycle is used because aside of water, hydrogen and oxygen, the chemical compounds used in these processes are continuously recycled.

  7. Octane - Wikipedia

    en.wikipedia.org/wiki/Octane

    Octane is a hydrocarbon and also an alkane with the chemical formula C 8 H 18, and the condensed structural formula CH 3 (CH 2) 6 CH 3.Octane has many structural isomers that differ by the location of branching in the carbon chain.

  8. Oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Oxygen_cycle

    The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as well as how it is used. The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions , oxides , and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [ 1 ]

  9. Oxygen-evolving complex - Wikipedia

    en.wikipedia.org/wiki/Oxygen-evolving_complex

    Photons trapped by photosystem II move the system from state S 0 to S 1 to S 2 to S 3 and finally to S 4. S 4 reacts with water producing free oxygen: 2 H 2 OO 2 + 4 H + + 4 e −. This conversion resets the catalyst to the S 0 state. The active site of the OEC consists of a cluster of manganese and calcium with the formula Mn 4 Ca 1 O x ...